2012 continues to be the year of surprise old-school comebacks, and next out the nostalgic blocks is Legend of Grimrock, an unashamedly adoring revisit of early 90s dungeon crawlers such as Ultima Underworld and Dungeon Master. Played from a first-person perspective, you control a squad of four hapless prisoners as they try to survive a maze of monster-filled tunnels underneath the titular mountain Grimrock.

Unlike the vast majority of today's roleplaying games, this isn't a matter of stabbing anything that moves and necking health potions at a rate that even Oliver Reed would raise an eyebrow at. Making it through Grimrock alive entails step-by-step caution, decision-making and puzzle-solving. The vintage, square-by-square movement system feels surprisingly natural rather than dated, and helps encourage carefully scouring every new section of wall you move towards for hidden buttons, messages and traps, or listening out for an approaching monster. Recklessness means falling down pits or finding yourself attacked from three sides at once.

Because the combat involves waiting for attack timers to recharge and selecting which of four characters will strike next, spamming attacks isn't possible - and in turn you can't speed-slaughter one enemy then turn quickly to the next. If you get yourself into a situation where you're being attacked on multiple fronts, you've done it wrong and all you can do is hope your last savegame is a recent one.

And while screenshots might suggest a constant parade of brown walls, really that's Grimrock's essential smartness. It's forever trying to lure you into a false sense of security, so you cease to pay attention. Each and any section of (impressively bump-mapped and tangibly oppressive) wall could be crucial to your progress. Grimrock is ultimately a particularly brutal puzzle game, where you need to pay constant attention and interpret environmental prompts to run its many gauntlets. Working out magic teleporter patterns, using physics and timing to throw rocks onto pressure points to activate remote doors, surviving apparently impossible fights by a sort of backwards chess that sees you blindly manoeuvring into safe spots even as a horde of skeletons rushes you...

It's not a game for the impatient, basically. Grimrock delights in tricks like tiny buttons disguised as bricks, keys hidden in darkened corners and the kind of lateral thinking that will likely drive even the most meticulous of players to online walkthroughs. Those didn't exist back in the early 90s, of course, which is one reason why it's so unforgiving - another is that it can an offer an in-game map function, whereas the likes of Dungeon Master required graph paper, a pencil and extreme feats of memory.

Grimrock achieves what it sets out to do so very confidently that chastising its smaller, primarily stylistic failings seems entirely petty. You could, if you really wanted, criticise its aesthetic sameiness, that the characters you play as are silent nobodies, that the monsters can look like figurines Photoshopped into the world rather than convincing life. To do so seems entirely cheerless - this is a game about being lost in a deep, dark dungeon, fearing what's around every corner and applying your eyes and brain to make your way past ever-ingenious obstacles.

While nominally you're controlling four assorted warriors, rogues and wizards (either a pre-fab party or hand-chosen by you), really it's you in there, in peril and being tested - hearing some chatter from your party or being coaxed into cooing at some setpiece would disrupt the dark immersion. A few puzzles can legitimately be criticised for being too obtuse, but at least the game is careful to keep you restricted to comparatively small areas at a time, so you shouldn't end up backtracking for miles and miles in the pursuit of an elusive solution.

A quiet, moody triumph. It's not for the impatient or easily-distracted, but it's for exactly that reason that Legend of Grimrock is such a substantial and atmospheric slice of thoughtful dungeoneering.

Free RPG Dungeon Crawl Stone Soup is one of a class of games known as roguelikes, after Rogue, the first such game. The ancient legacy is apparent. Although this open-source game has a graphics mode, it can also be played in straight ASCII, where your character is an "@" and the monsters are various letters or symbols. The "tiled mode" provides simple 2-D graphics.